It is widely understood that there are a variety of environmental exposures that have immense impact during pregnancy but much less impact at other times (e.g. folic acid deficiency, or fetal alcohol syndrome). There is also a lot of medical literature that points to links during particular time periods during pregnancy, or for that matter, development generally, that there is enhanced vulnerability to particular environmental conditions.
Generally speaking, these tend to be front loaded. The first trimester of pregnancy is a more vulnerable time, in general, than the third trimester, which is more vulnerable than the first year after birth, which is more vulnerable than preschool, which is more vulnerable to elementary school, until in adulthood, one is much, more robust.
I've seen charts describing what happens at particular stages of pregnancy and after birth developmentally. But, perhaps because I've never studied the right subjects in sufficient depth academically, I've never seen a chart really mapping out particular conditions arising from particular exposure periods (ideally, footnoted with peer reviewed journal references) in a comprehensive way. I would welcome anyone who can point me to such a chart in the comments, either with a link or a reference to a print source. I could embark on the task myself, but reinventing the wheel in this case would be a real waste.